Polymers made from polyhedral oligomeric silsesquioxanes and diacetylene-containing compounds

ABSTRACT

A compound having the formula below. Each R is methyl or phenyl; R 2  comprises one or more of silane, siloxane, and aromatic groups; n is a nonnegative integer; and m is 1 or 2. The dashed bond is a single bond and the double dashed bond is a double bond, or the dashed bond is a double bond and the double dashed bond is a triple bond. A polymer made by a hydrosilation reaction of a polyhedral oligomeric silsesquioxane having pendant siloxane groups with an acetylene- and silicon-containing compound having at least two vinyl or ethynyl groups, and a crosslinked polymer thereof. The reaction occurs between the pendant siloxane groups and the vinyl or ethynyl groups.

TECHNICAL FIELD

The disclosure is generally related to polymers containing polyhedraloligomeric silsesquioxane (POSS) groups.

DESCRIPTION OF RELATED ART

POSS systems have found use in hybrid inorganic/organic polymers.Ladder-like silsesquioxane polymers have found applications inphotoresist coatings for electronic and optical devices, interlayerdielectrics and protective coating films for semiconductor devices,liquid crystal display elements, magnetic recording media, optical fibercoatings, gas separation membranes, binders for ceramics and ascarcinostatic drugs (Li et al., J. Inorg. Organomet. Polym. 2002, 11(3),123-154). (All publications and patent documents referenced throughoutthis application are incorporated herein by reference.) In the area ofsurface modification and corrosion prevention, POSS systems have beenused as surface modifiers, dispersion agents, coupling agents,crosslinking agents, adhesion promoters, co-monomers, moisturescavengers and corrosion protection agents (Id.). In biomedical science,POSS has been used in place of fumed-silica which is typically used as afiller for improving the chemical, physical and biological properties ofmembranes used in immunoisolatory applications (Pittman et al., J.Macromol. Symp. 2003, 196, 301-325).

Polydiacetylenes, which may be obtained from the thermal polymerizationof diacetylenes, belong to materials that may change in response toexternal stimuli. Such materials are of interest due to the nature ofcoupled material responses, such as molecular structure and optical ormechanical properties. Interest in nanotechnology has added to thepotential uses of such materials due to the possibility of fabricatingdense arrays of nanodevices with built-in and measurable sensitivity toenvironmental conditions. Rapid sensing of dangerous biological agents(Charych et al., Science, 1993, 261, 585; Reichert et al., J. Am. Chem.Soc. 1995, 117, 829; Charych et al., Chem. Biol. 1996, 3, 113), micro-or nano-fluidic devices (Eddington et al., Lab on a Chip, 2001, 1, 96),or highly dense information storage (Albrecht et al., J. Vac. Sci.Technol. A, 1990, 8, 3386) are notable applications. Polydiacetylenes(PDAs) (Bloor et al., Polydiacetylenes: Synthesis, Structure, andElectronic Properties 1985 (Dordrecht: Martinus Nijhoff)) merit interestas these molecules may exhibit strong optical absorption andfluorescence emission that change dramatically with various stimuli,namely optical exposure (photochromism) (Day et al., Isr. J. Chem. 1979,18, 325; Tieke et al., J. Polym. Sci. A, 1979, 17, 1631; Olmsted et al.,J. Phys. Chem. 1983, 87, 4790; Carpick et al., Langmuir 2000, 16, 1270),heat (thermochromism) (Wenzel et al., J. Am. Chem. Soc. 1989, 111, 6123;Lio et al., Langmuir 1997, 13, 6524; Chance et al., J. Chem. Phys. 1977,67, 3616; Carpick et al., Langmuir 2000, 16, 4639; Lee et al.,Macromolecules 2002, 35, 4347), applied stress (mechanochromism)(Carpick et al., Langmuir 2000, 16, 1270; Muller et al., Mol. Cryst.Liq. Cryst. 1978, 45, 313; Nallicheri et al., Macromolecules 1991, 24,517; Tomioka et al., J. Chem. Phys. 1989, 91, 5694), changes in chemicalenvironment (Cheng et al., Langmuir 1998, 14, 1974; Jonas et al., J. Am.Chem. Soc. 1999, 121, 4580), and binding of specific chemical orbiological targets to functionalized PDA side-chains(affinochromism/biochromism) (Charych et al., Science, 1993, 261, 585;Reichert et al., J. Am. Chem. Soc. 1995, 117, 829; Charych et al., Chem.Biol. 1996, 3, 113). Other properties may include high third-ordernonlinear susceptibility, unique photo-conduction characteristics, andstrong nanometer-scale friction anisotropy (Carpick et al., Tribol.Lett. 1999, 7, 79). The linear nature of their structures may facilitatethe formation of uniformly separated linked moieties in a network. Inaddition, these ligands can be further converted to crosslinked systemsby interforming 1,2- or 1,4-addition of the neighboring units. This inessence yields the network a second-tier of crosslinks that can impartstructural reinforcement and additional spectroscopic properties to thenetwork. For example, networks containing crosslinked diacetylenes canexhibit various absorptions in the visible spectrum depending on theextent of the crosslinking. In such systems, ‘blue state’, ‘purplestate’ and ‘red state’ absorptions have been obtained which are eitherreversible or irreversible (Carpick et al., J. Phys.: Condens. Matter2004, 16, R679).

Hydrosilation is a reaction available for the construction ofinorganic-organic hybrid dendritic diacetylene-linked POSS networks.Hydrosilation reaction, the addition of a Si—H bond across anunsaturated organic moiety, has been used to create dendritic edificesof POSS materials, including one containing both POSS and carboraneclusters within its network (Kolel-Veetil et al., J. Polym. Sci. Part A:Polym. Chem., 2008, 46, 2581; US Patent Application Publication No.2009/0018273). The reactions involved ambient condition hydrosilationreactions of the reactants in the presence of the heterogeneoushydrosilation catalyst known as the Karstedt catalyst (platinum-divinylsiloxane catalyst). The reactions were performed in hexane or toluene.These facile reactions produced flexible and transparent network filmsof the anticipated products. Several other hydrosilation reactions havealso been reported for the production of networks containing POSSclusters (Bassindale et al., J. Mater. Chem. 1993, 3(12), 1319; Jaffreset al., J. Chem. Soc., Dalton, Trans., 1998, 2767-2770; Casado et al.,J. Appl. Organometal. Chem. 1999, 13, 245-259; Zhang et al., J. Am.Chem. Soc. 2000, 122, 6979; Saez et al., Chem. Eur. J. 2001, 7(13),2758-2764; Manson et al., J. Mol. Cat. A: Chem. 2002, 182-183, 99-105;Wada et al., Chem. Comm. 2005, 95-97; Chen et al., Thin Solid Films,2006, 514(1-2), 103-109; Seino et al., Macromolecules, 2006, 39,8892-8894).

BRIEF SUMMARY

Disclosed herein is a method comprising: reacting, by a hydrosilationreaction, a polyhedral oligomeric silsesquioxane having pendant siloxanegroups with an acetylene- and silicon-containing compound having atleast two vinyl or ethynyl groups to form a polymer. The reaction occursbetween the pendant siloxane groups and the vinyl or ethynyl groups.Also disclosed herein is a polymer made by the method, and a crosslinkedpolymer made by crosslinking the acetylene groups in the polymer. Alsodisclosed herein is a compound having the formula below. Each R ismethyl or phenyl; R² comprises one or more of silane, siloxane, andaromatic groups; n is a nonnegative integer; and m is 1 or 2. The dashedbond is a single bond and the double dashed bond is a double bond, orthe dashed bond is a double bond and the double dashed bond is a triplebond.

BRIEF DESCRIPTION OF THE DRAWINGS

A more complete appreciation of the invention will be readily obtainedby reference to the following Description of the Example Embodiments andthe accompanying drawings.

FIG. 1 schematically illustrates a hydrosilated network formed from POSSand diacetylene ligands.

FIG. 2 illustrates generally the crosslinking of a polydiacetylene.

FIG. 3 shows FT-IR spectra of 3a (top) and of 3b (bottom) depicting thediacetylene and vinyl absorptions.

FIG. 4 shows a DSC thermogram of the crystalline 3b, depicting themelting endotherm and the exotherm during the polymerization of thediacetylene moieties.

FIG. 5 shows DSC thermograms of 3a (hydrosilated) (top) and 3b(hydrosilated) (bottom) in N₂.

FIG. 6 shows TGA thermograms of 3a (hydrosilated) and 3b (hydrosilated)in N₂ and in air.

FIG. 7 shows FT-IR spectra of 3a (hydrosilated) (top) and of 3b(hydrosilated) (bottom) depicting the diacetylene absorption containedin the networks.

FIG. 8 shows FT-IR spectrum (top) and DSC thermogram (bottom) of a 3a(hydrosilated) film after thermal treatment at 150° C. for 4 h.

FIG. 9 is a schematic 2-dimensional depiction of the interdigitation ofpartially reacted 3a linkers bound to clusters of 1 involved in thesolid-state polymerization at ˜110° C. in 3a (hydrosilated).

FIG. 10 shows FT-IR spectrum of 3a (polymerized) exhibiting absorptionsof ene-yne (2132 cm⁻¹) and butatriene (1890 cm⁻¹) absorptions.

FIG. 11 illustrates the formation of ene-yne and butatriene groups.

FIG. 12 as a depiction of a dicarbene species and a diradical speciesgenerated during the thermal or photopolymerization of diacetylenes.

FIG. 13 shows the storage (G′) and loss tangent (tan δ) of the variousdendritic networks of this study. (top) 3a (hydrosilated) and 3a(polymerized). (bottom) 3b (hydrosilated) and 3b (polymerized). Plots A& B: G′. Plots C & D: tan δ.

DETAILED DESCRIPTION OF EXAMPLE EMBODIMENTS

In the following description, for purposes of explanation and notlimitation, specific details are set forth in order to provide athorough understanding of the present disclosure. However, it will beapparent to one skilled in the art that the present subject matter maybe practiced in other embodiments that depart from these specificdetails. In other instances, detailed descriptions of well-known methodsand devices are omitted so as to not obscure the present disclosure withunnecessary detail.

Disclosed herein is a method for the production of inorganic-organichybrid dendritic polymers containing cores of polyhedral oligomericsilsesquioxanes (POSS) clusters linked by acetylene-containingcrosslinkers, that may possess desirable thermal, thermo-oxidative,electrical, adhesive (coating/surface) and optical properties. Themethod utilizes hydrosilation reactions to construct the startingedifice of the acetylene-linked POSS dendritic systems and subsequentthermal polymerization of the acetylene linker ligands to createreinforced networked architectures that have potential for applicationsas smart coatings having thermal, photochemical, mechanical, andchemical responses.

Inorganic-organic hybrid polymers containing POSS clusters also have thepotential to function as space-survivable materials when used ascoatings owing to their surface adhesion on substrates and the abilityto protect bulk material from vacuum ultraviolet radiation degradationand atomic oxygen collisions (Phillips et al., Current Opinions in SolidState and Materials Science, 2004, 8, 21-29). Unlike the bonds oforganic molecules which undergo scission at about 4 eV, which is lowerthan the energy (5 eV) of atomic oxygen collisions, the Si—O bondrequires 8 eV for disruption. The facile oxidation of the POSS clustersto SiO₂ can generally provide a passivating layer over the substratewhen exposed to atomic oxygen collisions (Gilman et al., J. Apply.Polym. Sci. 1996, 60, 591-596; Gonzalez et al., J. Spacecraft Rockets,2000, 37, 463-467; Hoflund et al., J. Adhes. Sci. Technol. 2001, 15,1199-1211). Furthermore, an acetylene-linked POSS system may also havethe ability to absorb the vacuum ultraviolet radiation through itsdiacetylene groups resulting in the crosslinking of such groups and inthe reinforcement of the coating (Carpick et al., J. Phys.: Condens.Matter 2004, 16, R679).

Networks of POSS with rigid diacetylene linkers can also be targeted forforming materials of controlled porosity (Pielichowski et al., J. Adv.Polym. Sci. 2006, 201, 225-296). The cubic (RSiO_(1.5))₈ POSS octamersoffer 4,4′-cage structures with high surface area similar to those foundin zeolites (Breck D. W., Zeolite Molecular Sieves, 1984, Wiley, NewYork). In inorganic-organic hybrid dendritic systems containing suchPOSS clusters, the removal of the templated organic group such asdiacetylene by calcination, chemical oxidation, chemical rearrangementsor hydrolysis can further augment the porosity. Such a removal shouldprovide the system with pores whose size and shape will roughlycorrespond to that of the eliminated moiety. This strategy, which isused in the preparation of zeolites, has only recently been applied inhybrid sol-gel materials (Choi et al. (eds.), Photonic PolymerSynthesis, 1998, Marcel Dekker, NY, p 437). For example, the thermolysisof templated aryl- and ethynyl-linked silsesquioxanes was observed toproduce porous structures upon removal of the organic linkers (Shea etal., J. Am. Chem. Soc. 1992, 114, 6700). In an alternative approachdeveloped at low temperature, inductively coupled plasma was used toburn away organic linking groups in crosslinked polysilsesquioxanexerogels thereby producing porous silica gels (Loy et al., J.Non-Crystal Solids, 1995, 186, 44; Loy et al., Mater Res Soc Symp. Proc(Adv Porous Mater), 1995, 371, 229).

Disclosed herein is a method to achieve the simultaneous incorporationof POSS and PDA in a polymeric system by the hydrosilation reactions ofPOSS and acetylene (DA)-containing monomers. POSSs have the generalformula (RSiO_(1.5))_(a)(H₂O)_(0.5b) or rearranged toR_(a)Si_(a)O(_(1.5a-0.5b))(OH)_(b), where a is a positive integer, b isa non-negative integer, a+b is a positive even integer, and b≦a+2. In acompletely condensed POSS, b is zero and all Si—O—Si bridges arecomplete. In an incompletely condensed POSS, some adjacent pairs ofsilicon atoms are not bridged, each containing an OH group. SuitablePOSSs include, but are not limited to, ((SiH(CH₃)₂O)SiO_(1.5))₈ 1(octasilanePOSS), in which a=8, b=0, and R=SiH(CH₃)₂O—.

The POSS is reacted with an acetylene- and silicon-containing compoundhaving at least two vinyl or ethynyl groups that can undergo thehydrosilation reaction. The compound may have two terminal vinyl orethynyl groups and include siloxane and/or aromatic groups. The phrase“at least two vinyl or ethynyl groups” includes all vinyl groups, allethynyl groups, and combinations of vinyl and ethynyl groups. Thecompound may itself be the reaction of a divinyl compound andsilicon-containing compound in a 2:1 molar ratio, as in compounds 4a,4b, 5a, 5b, 6a, and 6b. The compound may be made with other molarratios. Regardless of the ratio, formation of the compound may produce amixture of oligomers of different lengths, with no particular maximumlength. Thus, the value of n in the compound disclosed in the BriefSummary is a nonnegative integer (including 0), and the polymer caninclude a combination of compounds having different values of n. Theaverage value of n is determined by the molar ratio used when making thecompound. Vinyl silane groups may be added to diacetylene groups asshown in the scheme below. The value of m may be 2 for a diacetylenecompound, or 1 for a single acetylene group. Suitable compounds forreaction with the POSS include, but are not limited to, 3a, 3b, 4a, 4b,5a, 5b, 6a, 6b, 7a, and 7b shown below. In the examples using thesecompounds, the average value of n is 1, but compounds include acombination of compounds having different values of n. Any of the silylmethyl groups may also be other alkyl or aryl groups. The compound mayor may not be free of carborane groups.

The silyl hydrogens react with the vinyl or ethynyl groups of thecompound. This is shown below for the reaction of a single vinyl groupwith a single silane. FIG. 1 schematically illustrates a hydrosilatednetwork formed from POSS and diacetylene ligands. This may be performedin the presence of the Karstedt catalyst, Pt₂{[(CH₂═CH)Me₂Si]₂O}₃. Thereaction may occur regardless of the particular POSS core ordiacetylene- and silicon-containing vinyl compound used. The thermalstability of the networks can be attributed to the barrier effect tooxygen of POSS-containing systems (Ascuncion et al., Macromolecules,2007, 40, 555) and on limited molecular mobility that POSS systemspossess due to POSS-POSS interactions (Haddad et al., Macromolecules,1996, 29, 7302).

There may be diminished reactivity of the vinyl groups when there arephenyl groups on the Si atoms, as in 3b, in comparison to when there aremethyl groups on the Si atoms, as in 3a. This is presumed to be due tothe steric encumbrance caused by the two bulkier phenyl groups on the Siatom containing the vinyl group in 3b in comparison to the twosterically less demanding methyl groups on the Si atom that contain thevinyl group in 3a. Similar effects of steric factors on the rates ofaddition of Si—H across double bonds are known and the additions havebeen reported to occur more facilely at the least hindered side or face(when the hydrosilated ligand is of a cyclic type) (Weng et al.,Heteroatom. Chem. 1995, 6(1), 15; Trofimov et al., J. Org. Chem. 2007,72(23), 8910).

After formation of the hydrosilated network, the acetylene groups may becrosslinked to form a crosslinked polymer. This may be done by heatingunder an inert gas. During solid-state polymerization of diacetylenes,elongated polymer chains can be formed under preservation of thestarting crystalline phase structure provided that the molecular motionsaccompanying chemical transformation compensate each other in a way tominimize the overall changes of the crystallographic parameters (Wegner,Naturforsch, 1969, 24B, 824; Baughman, J. Appl. Phys. 1972, 43, 4362).The removal of the diacetylene groups in such thermo-oxidatively-treatednetworks by calcination, chemical oxidation or hydrolysis can beexpected to yield highly porous materials similar to zeolites with highsurface area (Loy et al., J. Non-Crystal Solids, 1995, 186, 44; Loy etal., Mater Res Soc Symp. Proc (Adv Porous Mater), 1995, 371, 229).

It is known that the dicarbene or the diradical moieties (FIG. 12)function as chain initiators for the formation of an ene-yne or abutatriene-type of polymerization, respectively. In the case of thediradical intermediate, its energy of formation is lower than that ofthe dicarbene moiety, since its formation requires the disruption ofonly one C—C π-bond instead of two in the case of a dicarbene (Bässleret al., Polydiacetylenes, Advances in Polym. Sci. Vol. 63,Springer-Verlag, Berlin, 1984). It has been established by ESR work(Hori et al., J. Am. Chem. Soc. 1979, 101, 3173) and opticalspectroscopy (Tobolsky, Properties and Structures of Polymers, Wiley,New York, 1960) that the diradical mechanism is in operation during thegrowth of oligomeric chains up to length of 5 repeat units. However,upon further addition of diacetylene units, the acetylenic structurebecome energetically more stable causing a cross-over to the dicarbenemechanism. Thus, in 3a (hydrosilated) and 3b (hydrosilated), thereactive species that is formed initially during the polymerization, asseen in the FT-IR spectrum, is the diradical species formed below atemperature of 100° C. during the polymerization in both ordered anddisordered domains in the networks. Subsequently, as the polymerizationtemperature is increased, the diradical species that are present in theordered domains undergo polymerization more easily, first to a shortrange order (n=5 repeat units) as diradical species and then undertake adicarbene polymerization mechanism resulting in the formation oflong-range ordered (n≧6 repeat units) polymerized diacetylene units inthe networks in the temperature range of 100-140° C.

In some case, approximately one-third of the diacetylene units arebelieved to be participating in a long-range order polymerization,suggesting that approximately one-third of the linkers stay bound atonly one of its termini to the POSS clusters. However, the remainingdiradical species which are present mainly in the disordered amorphousregions remain less favorably positioned to find one another and reactfurther. In order to facilitate their reactions, additional thermalenergy may have to be supplied to the networks which may result in thethermal randomization of the domains and the eventual reaction of thesediradical species within a short range order (n=5 repeat units) to formpolymerized domains between the temperature range of 250-325° C.

The inorganic-organic hybrid dendritic polymers, containing cores ofpolyhedral oligomeric silsesquioxanes (POSS) clusters linked bydiacetylene-containing crosslinkers are network polymers that containuniformly spatially separated POSS units by diacetylene linkers. ThePOSS clusters are known for their exceptional chemical and materialproperties. In addition, the potential for exceptionalstimuli-responsive properties (photochromism, thermochromism,mechanochromism and affinochromism/biochromism) of the PDA ligandsproduced in these dendritic networks make them candidates forapplications such as smart coatings. Based on thermo gravimetric anddifferential scanning calorimetric analyses, the exceptional thermal andthermo-oxidative stabilities (revealed by the high char yields in airand in N₂) and the elastomeric properties (revealed by the low T_(g)'s)of the systems have already been demonstrated. The observation ofirreversible red colored crosslinked networks (“red form”) formed onthermal polymerization suggests that stimuli-responsive materials can beformed from these systems by controlling the extent of the thermalpolymerization to a reversible stage such as a “purple form” or a “blueform” (Carpick et al., J. Phys.: Condens. Matter 2004, 16, R679). Inaddition, the diacetylene groups that are tethered around the rigid POSSclusters are also spatially constrained to a greater extent than inother typical diacetylene-containing polymers. This enhanced spatialseparation/resolution of both POSS and diacetylene ligands bode well forthe utilization of the invented materials in applications that requiresstructural constraints.

During polymerization of a hydrosilation product, two increases instorage modulus (G′) may be seen corresponding to two distinct thermalpolymerization events of diacetylenes. The enhancements in the G′ valuemay be followed by a decrease in G′. Such decreases in the moduli ofcured diacetylene-containing systems have been attributed to anexcessive level of diacetylene polymerization leading to excessivenetwork formation and a reduction of the structural properties(Tobolsky, A. V. Properties and Structures of Polymers, Wiley, New York,1960). This decrease in the moduli has been further linked to the harddomains in the network that are formed under such conditions which arerendered non-deformable under high-strain conditions thereby nullifyingan improvement in the domains' cohesion by the development of strongernonbonded forces. Such domain cohesion was achieved only under anoptimum level of diacetylene polymerization (Id.).

Using similar reaction conditions as with 3a and 3b, 7a and 7b can beindividually reacted with Octasilane-POSS 1 to form 7a (hydrosilated)and 7b (hydrosilated), respectively. The conversion of 7a (hydrosilated)and 7b (hydrosilated) to 7a (polymerized) and 7b (polymerized),respectively, can be achieved by thermal means (Fan et al., Polym. Int.2006, 55, 1063-1068; Fan et al., Polym. Bull. 2006, 56(1), 19-26) or bythe use of a transition metal-based catalyst (Masuda et al., Acc. Chem.Res. 1984, 17, 51-56; Masuda et al., Macromolecules 1989, 22(3),1036-1041).

The following examples are given to illustrate specific applications.These specific examples are not intended to limit the scope of thedisclosure in this application.

Example 1

Materials and Instrumentation—The POSS monomer OctaSilanePOSS® (1) andthe Karstedt catalyst (platinum-divinyl tetramethyldisiloxane complex inxylene, 2.1-2.4% Pt) were procured from Hybrid Plastics, Inc. andGelest, Inc., respectively, and were used as received.Vinyldimethylchlorosilane and vinyldiphenylchlorosilane, from Gelest,Inc., were distilled under argon at their boiling points, 82° C. and125° C., respectively, prior to use. Toluene (anhydrous, 99.8%),N-butyllithium (n-BuLi, 2.5 M solution in hexanes), tetrahydrofuran(THF, anhydrous, 99.9%), diethyl ether (Et₂O, anhydrous, 99.5%),chloroform-d (CDCl₃, 99.6+ atom % D), ammonium chloride (NH₄Cl, 99.5+%),granular sodium sulfate (Na₂SO₄, anhydrous, 99+%), activated carbon(Darco® 41-2 mesh, granular) and filter agent, Celite® 521 (celite) wereall obtained from Aldrich and used as received. Hexachloro-1,3-butadiene(C₄Cl₆, 97%, Aldrich) was vacuum-distilled (220 mT, 49.5° C.). Note:C₄Cl₆ is toxic as are most other chlorinated reagents. The reactionscheme for the synthesis of the diacetylene-containing monomer (3a or3b) is depicted above. The syntheses were performed under an atmosphereof dry argon utilizing standard Schlenk techniques. Thermogravimetricanalyses (TGA) were performed on a SDT 2960 simultaneous DTA-TGAanalyzer. The differential scanning calorimetry (DSC) studies wereperformed on a DSC 2920 modulated DSC instrument from −60° C. to 400° C.All thermal experiments (TGA and DSC) were carried out with heatingrates of 10° C./min and nitrogen or air flow rate of 100 cm³/min.Infrared (IR) spectra were obtained on NaCl plates for the startingmaterials and as thin films of the various produced dendritic networksusing a Nicolet Magna 750 Fourier transform infrared spectrometer.Solution-state ¹H and ¹³C NMR spectra were acquired on a Bruker AC-300spectrometer and referenced to the peak of the internal solvent, CDCl₃.Rheological measurements were performed from ambient temperature to 400°C. in a nitrogen atmosphere on a TA Instruments AR-2000 rheometer inconjunction with an environmental testing chamber for temperaturecontrol. Measurements on rectangular solid samples were carried out inthe torsion mode at a strain of 2.4×10⁻⁴ and a frequency of 1 Hz.Samples were prepared in silicone molds with cavity dimensions 52 mm×12mm×10 mm by transferring flowable reaction mixtures into the molds toallow further gelation and concurrent expulsion of solvent at roomtemperature. The storage modulus (G′) and loss tangent (tan δ) weredetermined as a function of temperature in the 25-400° C. temperaturerange at a heating rate of 3° C./min.

Example 2

Synthesis of 3a and 3b—Anhydrous THF (50 mL) and n-BuLi (46.7 mL, 2.5 M,116.75 mmol) were transferred to a sealed 50-mL Kjeldahl reaction flaskcontaining a magnetic stir bar. The reactions flask had been evacuatedunder vacuum and back-filled with argon prior to the additions. Theflask was then immersed in a dry ice/2-propanol bath. While stirring,C₄Cl₆ (5 mL, 32 mmol) was added dropwise over 20 min, forming a blue,then purple, and then black solution. The dry ice/2-propanol bath wasremoved and the reaction mixture was warmed to room temperature withstirring over 2 h. The mixture was then cooled further in a dryice/2-propanol bath and vinyldimethylchlorosilane (8.3 mL, 60 mmol) orvinyldiphenylchlorosilane (13.5 mL, 60 mmol) was added drop wise toinitiate the formation of 3a or 3b, respectively. The reaction mixturewas further warmed to room temperature with stirring over 2 h and thecontents were then poured into a saturated NH₄Cl solution (150 mL,aqueous) at 0° C. The reaction flask was then rinsed with Et₂O into theNH₄Cl quench solution. The resulting two-phase mixture was transferredto a 500-mL separatory funnel and washed with a saturated NH₄Cl (aq)solution until the pH was neutral and then two times with distilled H₂O.The dark organic phase was poured into an Erlenmeyer flask and driedover anhydrous Na₂SO₄ and activated carbon. The dried solution wasfiltered through celite into a round-bottomed flask, concentrated byrotary evaporation, and then exposed to reduced pressure at roomtemperature for 5 h. In the case of 3a, a brownish red solution wasobtained. Distillation of this brownish red solution yielded 3a as aclear reagent. In the case of 3b, a brownish red solid was collected.Crystallization of the solid from its concentrated solution in Et₂Oyielded pale red crystals of the (divinyldiphenylsilyl)-μ-diacetylidereagent.

FT-IR: 3a: ν (—C≡C—C≡C—): 2069 cm⁻¹ and ν (—CH═CH₂): 1594 cm⁻¹ (FIG. 3).3b: ν (—C≡C—C≡C—): 2070 cm⁻¹ and ν (—CH═CH₂): 1594 cm⁻¹ (FIG. 3). ¹H NMR(in ppm): 3a: 6.18-5.83 (—CH═CH₂) and 0.261 (—CH₃). 3b: 7.68-7.38(C₆H₅—) and 6.510-5.990 (—CH═CH₂). ¹³C NMR (in ppm): 3a: (135.76,134.62) (—CH═CH₂) (sp² C), (89.62, 84.79) (—C≡C—C≡C—) (sp C) and −1.27(—CH₃) (sp³ C). 3b: (132.25, 131.87) (—CH═CH₂) (sp² C), (91.89, 81.90)(—C≡C—C≡C—) (sp C) and (138.04, 135.41, 130.45, 128.11) (C₆H₅—) (sp² C).DSC analysis (from RT to 400° C. at 10° C./min) in N₂ of 3b: Meltingendotherm at 101° C. and exotherm at 307° C. (FIG. 4).

Example 3

Formation of the inorganic-organic hybrid hydrosilated dendriticnetwork, 3a (hydrosilated), from reaction of 1 and 3a—Octasilane-POSS 1(0.5 g, 0.49 mmol) and 3a (0.43 g, 1.96 mmol) were mixed with 2.5 mL oftoluene to yield a clear solution. To this solution, 45 μL (4.95 μmol ofPt) of the Karstedt catalyst solution was added and the mixture wasmixed vigorously for 2 min using a mechanical stirrer. The solution tookon a pale yellow hue indicating the initiation of the hydrosilationreaction. The mixture was then transferred into a Teflon mold tofacilitate the formation of a clear and transparent film at ambientconditions. DSC analysis of a 3a (hydrosilated) film sample under a flowof N₂: An endotherm at 20° C. and exotherms at 114° C. and 306° C. wereobserved in the thermogram (FIG. 5). TGA analysis of a 3a (hydrosilated)film sample: In N₂, a 5% weight loss was observed at 485° C. and theweight retention at 1000° C. was 81%. In air, a 5% weight loss occurredat 400° C. and the weight retention at 1000° C. was 73% (FIG. 6).

Example 4

Thermal polymerization of the diacetylene units in 3a (hydrosilated) toform 3a (polymerized)—A well-formed film of 3a (hydrosilated) wasthermally ramped under argon in an oven to 400° C. in an hour and washeated at this temperature for 2 h. Subsequently, the film was cooled toroom temperature in 1 h. This resulted in the formation of a dark red 3a(polymerized) film. TGA analysis of a 3a (polymerized) film sample: InN₂, a 5% weight loss occurred at 587° C. and the weight retention at1000° C. was 88%. In air, a 5% weight loss occurred at 448° C. and theweight retention at 1000° C. was 79% (FIG. 6).

Example 5

Formation of the inorganic-organic hybrid hydrosilated dendritic network3b (hydrosilated) from reaction of 1 and 3b—Octasilane-POSS 1 (0.50 g,0.49 mmol) and 3b (0.91 g, 1.97 mmol) were mixed with 2.5 mL of tolueneto yield a clear solution. To this solution, 90 μL (9.90 μmol of Pt) ofthe Karstedt catalyst solution was added and the mixture was mixedvigorously for 5 min using a mechanical stirrer. The solution remainedclear indicating that the initiation of the hydrosilation reaction hadnot occurred. Hence, the mixture was transferred into a Teflon mold andwas heated on a hot plate at 80° C. for 1 h to facilitate the formationof a clear and transparent film. DSC analysis of a 3b (hydrosilated)film sample in N₂: An endotherm at 20° C. and exotherms at 112° C. and302° C. were observed in the thermogram (FIG. 5). TGA analysis of a 3b(hydrosilated) film sample: In N₂, a 5% weight loss occurred at 164° C.and the weight retention at 1000° C. was 74%. In air, a 5% weight lossoccurred at 218° C. and the weight retention at 1000° C. was 49% (FIG.6).

Example 6

Thermal polymerization of the diacetylene units in 3b (hydrosilated) toform 3b (polymerized)—A well-formed film of 3b (hydrosilated) wasthermally ramped under argon in an oven to 310° C. in an hour and washeated at this temperature for 2 h. Subsequently, the film was cooled toroom temperature in 1 h. This resulted in the formation of a dark red 3b(polymerized) film.

The crystalline linker 3b was further investigated to ascertain whetherits diacetylene groups could be polymerized by thermal means in itssolid-state. The DSC thermogram of the crystalline 3b, exhibited amelting endotherm at 101° C. and broad exotherm at 307° C. (FIG. 4).Therefore, it appears that in 3b, the thermal polymerization of thediacetylene triple bonds occurs in a disordered amorphous phase and notin a solid-state (crystalline state) (Corriu et al. J. Organomet. Chem.1993, 449, 111).

During the formation of the dendritic networks from 1 and 3a or 3b, theonset and progress of the reaction was monitored by the FT-IRcharacterization of the reaction mixture. A gradual disappearance of thevinyl absorption of 3a or 3b at 1594 cm⁻¹ and 1589 cm⁻¹, respectively,and the disappearance of the Si—H absorption at 2140 cm⁻¹ of theoctasilane-POSS (FIG. 7) indicated the progress of the reaction. Theaddition of the linker alkenes 3a and 3b was found to follow bothMarkonikov and anti-Markonikov modes during the addition to one of itstermini, as determined by reactions of ligands to them, which are to bepublished elsewhere. After the initial hydrosilation reactions, thediacetylene absorptions in both 3a (hydrosilated) and 3b (hydrosilated)networks appeared at 2070 cm⁻¹. However, some unreacted vinyl groups of3a and 3b and unreacted Si—H groups of 1 were also observed in the FT-IRspectrum of the reaction products. Thus, it appears that all of the 8reactive Si—H bonds in a POSS cluster may not be accessible for reactionat ambient temperature with the terminal vinyl groups in 3a and 3b dueto steric crowding around the POSS cluster. This situation in thegenerated networks is not surprising considering the fact that thelinker groups 3a and 3b are not particularly long. Soxhlet extractionsof the products were performed in toluene to determine whether there wasany unreacted 3a or 3b entrapped in the network. The small amount of solfraction (less than 2%) suggested that almost the entire amount of thelinkers were bound, at least at one of their termini, to the POSSclusters in the generated networks. The progress of the reaction canalso be monitored by ¹H and ¹³C NMR spectroscopy. Incidentally, thereaction of 1 with 3a was found to proceed facilely at room temperaturein comparison to its reaction with 3b, which was found to be sluggish atambient temperature. In order to obtain a similar extent of reaction of1 with 3b as with 3a, the mixture of 1 and 3b had to be treated withtwice the amount of the Karstedt catalyst and had to be heated at 80° C.for 1 h.

The hydrosilated network 3a (hydrosilated), with intact internaldiacetylene groups, was observed to be extremely thermally stable asevidenced by its high temperature of degradation (temperature of 5%weight loss) of 485° C. and its high weight retention of 81% at 1000° C.when heated in a N₂ atmosphere (FIG. 6). The 19% weight loss at 1000° C.corresponded to a loss of about three-quarters of the labile Si-boundmethyl groups in the network, since Si, O, and the carbons of thediacetylene groups are not known to be lost at such conditions unlesspresent in pendant groups (Corriu et al. J. Organomet. Chem. 1993, 449,111; Corriu et al., Chem. Mater. 1996, 8, 100). In this regard, of thetotal 32 methyl groups in a repeat dendritic unit in 3a (hydrosilated),half of the Si-bound methyl groups belong to the peripheral Si atoms ofthe dimethylsiloxyl groups of 1 and the other half are bound to the Siatoms of the 3a linker. The ˜19% weight loss corresponds to a loss of 24Si-bound methyl groups. Of particular interest, then, is the question asto which of the Si-methyl groups gets retained upon crosslinking andformation of 3a (hydrosilated). An answer to this becomes apparent whenthe TGA thermogram of 3b (hydrosilated) network is analyzed (FIG. 4). In3b (hydrosilated), there are 16 Si-bound methyl groups on the peripheralSi atoms of the dimethylsiloxyl groups of 1 and 16 Si-bound phenylgroups on the Si atoms of 3b linker. The weight loss of ˜26% at 1000° C.in this network requires that at least 8 phenyl groups of the linkerligand be retained in the final product, since a loss of all the phenylgroups of 3b would have brought the final char yield to around 55%. Byextrapolation, it appears that the retention of 8 methyl groups and 8phenyl groups on thermal treatment of 3a (hydrosilated) and 3b(hydrosilated) to 1000° C. in N₂, respectively, occurs at the Si atomsof the linkers 3a and 3b. Similarly, the weight loss, at 1000° C. inair, of 27% for 3a (hydrosilated) and of 51% for 3b (hydrosilated)represent a complete loss of all the pendant methyl and phenyl groups inthe two systems. This suggests that the treatment of 3a (hydrosilated)and 3b (hydrosilated) to 1000° C. in air should yield dendritic systemscontaining only crosslinked diacetylene groups as the organicfunctionality.

In investigating the thermal polymerization of diacetylenes in 3a(hydrosilated) and 3b (hydrosilated), it was of interest to determinewhether the thermal polymerization of the diacetylene groups occurred ina solid-state or rather in a disordered amorphous phase, as observed in3b. The DSC thermogram of 3a (hydrosilated) (FIG. 5) exhibited anendotherm at 20° C. and exotherms at 114° C. and 306° C. However, animportant aspect to consider was whether the two exotherms were a resultof distinct events of diacetylene polymerizations in 3a (hydrosilated).Since the exotherm at 306° C. was presumed to have originated from thethermal polymerization of diacetylenes, for example as observedsimilarly in 3b, it was necessary to determine the origin of the 114° C.exotherm. Hence, a film of 3a (hydrosilated) was treated at 150° C. for4 h in N₂ to ensure the completion of the exothermic event around 114°C. During this thermal treatment, the sample took on a red huesuggestive of the thermal polymerization of diacetylenes. The FT-IRspectrum and the DSC thermogram of the treated sample were obtained tofurther examine the origin of the exothermic event (FIG. 8). The FT-IRspectrum exhibited the retention of the vibrations of unreacted Si—Hbonds of 1 and the vinyl groups of 3a. This suggested that the exothermat 114° C. originated from the thermal polymerization of diacetylenesand not from another exothermic event such as the reaction of anyresidual Si—H bonds of 1 and the vinyl groups of 3a. In addition, theDCS thermogram of the treated sample to 400° C. in N₂ exhibited only asingle exotherm at 315° C., indicating the complete disappearance of thediacetylene units in 3a (hydrosilated) that caused polymerizationattributed to the exotherm at 114° C. Thus, it appears that the lowerexotherm at 114° C. represents a solid-state type polymerization ofdiacetylenes and the higher exotherm at 306° C. belongs to apolymerization of diacetylenes in an amorphous disordered state in 3a(hydrosilated). The solid-state type regions in 3a (hydrosilated)probably originated from the interdigitation of diacetylene unitsbelonging to proximal partially reacted (bound at a single terminus) 3alinkers attached to clusters of 1 as shown in FIG. 9. The lowtemperature (114° C.) of the initial exotherm for this solid-statepolymerization of the diacetylenes in an ordered crystalline-like phasein comparison to the higher temperature (306° C.) for the diacetylenepolymerization in the disordered amorphous regions is not surprisingconsidering reports that solid-state polymerization of diacetylenes canoccur even at room temperature and very easily at 80° C. (Bloor et al.,J. Mater. Sci. 1975, 10, 1678; Wegner, Makromol. Chem. 1972, 154, 35). Asimilar DSC thermogram (FIG. 5) was also observed for 3b (hydrosilated)with an endotherm at 20° C. and exotherms at 112 and 302° C., whichsuggested that the dendritic systems in the two cases were very similar.

The operation of two distinct events of thermal polymerization ofdiacetylene units during the thermal treatment of 3a (hydrosilated) isapparent in the FT-IR spectrum of the resulting polymerized product 3a(polymerized) (FIG. 10), which was obtained upon the complete thermalpolymerization of the diacetylene units in 3a (hydrosilated) heated to400° C. The absorptions at 2132 and 1890 cm⁻¹ in the FT-IR spectrum canbe attributed to ene-yne (Helveger et al., J. Polym. Sci. Part B. Polym.Phys. 1989, 27, 1853) and butatriene (West et al., J. Organomet. Chem.1970, 23, 53) functionalities, respectively, that are produced uponthermal polymerization of the diacetylene units of 3a (hydrosilated) tovarying degrees of repeat units. From the area under the exotherms at˜110° C. in the DSC thermograms of both 3a (hydrosilated) and 3b(hydrosilated), approximately one-third of the diacetylene units arebelieved to be participating in such a long-range order polymerization,suggesting that approximately one-third of the 3a or 3b linkers staybound at only one of its termini to the clusters of 1. This explains theobserved unreacted Si—H and vinyl absorptions of 1 and 3a or 3b,respectively, in the FT-IR spectrum of 3a (hydrosilated) and 3b(hydrosilated).

Example 7

Rheological measurements of 3a (hydrosilated), 3b (hydrosilated), 3a(polymerized) and 3b (polymerized)—Rheological measurements wereperformed on rectangular solid samples formed from 3a (hydrosilated) and3b (hydrosilated) networks, and their thermally polymerized versions, 3a(polymerized) and 3b (polymerized), to determine more accurately theT_(g) of the networks and to measure their mechanical stiffness(modulus) (FIG. 13). The storage modulus (G′) of the “as prepared” 3a(hydrosilated) (˜130 MPa) was determined to be higher than that of asimilar sample of 3b (hydrosilated) (˜100 MPa). The T_(g), taken as themaximum in tan δ, was observed to be lower for 3a (hydrosilated) (46°C.) relative to 3b (hydrosilated) (51° C.). In addition, a slightlybroader tan δ peak for 3b (hydrosilated) suggested a broader range ofrelaxation times during the glassy to rubbery transition than in 3a(hydrosilated). During the thermal scan of 3a (hydrosilated) from 25 to400° C., a steady increase in the storage modulus was observed after itsT_(g), starting from and corresponding to its first exotherm at ˜115° C.in its DSC. During the progression of the run, a further dramaticincrease in G′ from 200 MPa to 325 MPa was observed from 300 to 330° C.,enveloping the region of the second major exotherm at 306° C. in itsDSC. These two increases in G′ correspond to the two distinct thermalpolymerization events of diacetylenes in 3a (hydrosilated). Theenhancements in the G′ value was followed by an equally dramaticdecrease in G′ finally stabilizing at a value of ˜190 MPa near 400° C.(Wegner, Naturforsch, 1969, 24B, 824; Baughman, J. Appl. Phys. 1972, 43,4362). It is presumed that above 330° C., further polymerizationprobably reduced G′ of 3a (hydrosilated) due to the formation ofpossible non-deformable domains in the network. To verify this, a sampleof 3a (hydrosilated) was initially thermally treated to 400° C. in N₂ toproduce 3a (polymerized) and subsequently its G′ was evaluated. The G′value at ambient temperature was found to be equal to ˜190 MPa asobtained for 3a (hydrosilated) at 400° C. during its rheological run.The thermal treatment of 3b (hydrosilated) to 400° C. in N₂ for 2 h, onthe other hand, was found to produce an extensively brittle sample,which was found not usable for rheological evaluations, indicating thatupon diacetylene polymerization an even greater degree of non-deformabledomains were formed in such a sample than in 3a (polymerized). Hence, asample of 3b (hydrosilated) was treated to 310° C. for 1 h to produce anintact sample of 3b (polymerized) and a rheological measurement wasperformed on this sample. As anticipated, the G′ (˜140 MPa) of thissample at ambient temperature was found to be higher than that of theambient temperature G′ (˜100 MPa) of the “as prepared” 3b(hydrosilated).

Example 8

Synthesis of the crosslinker 4a from 3a and1,4-bis(dimethylsilyl)benzene—1,4-Bis(dimethylsilyl)benzene (0.1 g,0.514 mmol) and 3a (0.225 g, 1.028 mmol) were mixed in 2 mL of hexane ina vial and 90 μL (9.90 μmol of Pt) of the Karstedt catalyst solution wasadded and the mixture was mixed vigorously for 2 min using a mechanicalstirrer to obtain a viscous product. FT-IR: ν (—C≡C—C≡C—): 2072 cm⁻¹ andν (—CH═CH₂): 1596 cm⁻¹. ¹H NMR (in ppm): 7.67 (C₆H₅—), 6.22-5.86(—CH═CH₂) and (0.473 (of 1,4-bis(dimethylsilyl)benzene), 1.84(—Si—CH₂—CH₂—Si—, sp² C), 0.278 (of 3a)) (—CH₃). ¹³C NMR (in ppm):(138.76, 133.66) (—CH═CH—, phenyl) (136.26, 134.92) (—CH═CH₂, alkene)(sp² C), (89.98, 85.04) (—C≡C—C≡C—) (sp C), 1.52 (—Si—CH₂—CH₂—Si—, spC), and (−1.02, −3.12) (—CH₃) (sp³ C).

Example 9

Formation of the inorganic-organic hybrid hydrosilated dendritic network4a (hydrosilated) from reaction of 1 and the crosslinker4a—Octasilane-POSS 1 (0.50 g, 0.49 mmol) and 4a (1.24 g, 1.97 mmol) weremixed with 2.5 mL of toluene to yield a clear solution. To thissolution, 90 μL (9.90 μmol of Pt) of the Karstedt catalyst solution wasadded and the mixture was mixed vigorously for 5 min using a mechanicalstirrer. The mixture was transferred into a Teflon mold and was heatedon a hot plate at 80° C. for 1 h to facilitate the formation of a clearand transparent film. DSC thermogram of the product from 25° C. to 400°C.: Exotherms at 125° C. and 320° C.

Example 10

Thermal polymerization of diacetylene linkers in 4a (hydrosilated) toform 4a (polymerized)—A sample of a clear film of 4a (hydrosilated) wastreated in argon in a tube furnace at 250° C. for 30 min and at 400° C.for 2 h. The film was subsequently cooled to room temperature. The colorof the film had changed to dark red (“red form”) due to irreversiblethermal polymerization. Glass transition temperatures (T_(g)) (from −60°C. to 400° C. @ 10° C./min) of the film: 18.52° C., 49.24° C.; Noexotherms were observed as all diacetylene units had crosslinked onthermal polymerization.

Example 11

Synthesis of the crosslinker 4b from 3b and1,4-bis(dimethylsilyl)benzene—1,4-Bis(dimethylsilyl)benzene (0.1 g,0.514 mmol) and 3b (0.480 g, 1.028 mmol) were mixed in 2 mL of hexane ina vial and 90 μL (9.90 μmol of Pt) of the Karstedt catalyst solution wasadded and the mixture was mixed vigorously for 2 min using a mechanicalstirrer to obtain a viscous product. FT-IR: ν (—C≡C—C≡C—): 2072 cm⁻¹ andν (—CH═CH₂): 1596 cm⁻¹. ¹H NMR (in ppm): 7.68-7.38 (C₆H₅—) (of 3b)),7.72 (C₆H₅—) (of 1,4-bis(dimethylsilyl)benzene), 6.58-6.05 (—CH═CH₂)1.92 (—Si—CH₂—CH₂—Si—, sp² C), and (0.473) (—CH₃). ¹³C NMR (in ppm):(138.23, 135.82, 130.58, 128.25) (C₆H₅— of 3b) (sp² C) (138.82, 133.74)(—CH═CH—, phenyl of 1,4-bis(dimethylsilyl)benzene) (136.26, 134.92)(—CH═CH₂, alkene) (sp² C), (89.98, 85.04) (—C≡C—C≡C—) (sp C), 1.62(—Si—CH₂—CH₂—Si—, sp² C), and (−3.12) (—CH₃) (sp³ C). DSC analysis (fromRT to 400° C. at 10° C./min) in N₂ of 4b: Melting endotherm at 105° C.and exotherm at 315° C.

Example 12

Formation of the inorganic-organic hybrid hydrosilated dendritic network4b (hydrosilated) from reaction of 1 and the crosslinker4b—Octasilane-POSS 1 (0.50 g, 0.49 mmol) and 4b (2.22 g, 1.97 mmol) weremixed with 2.5 mL of toluene to yield a clear solution. To thissolution, 90 μL (9.90 μmol of Pt) of the Karstedt catalyst solution wasadded and the mixture was mixed vigorously for 5 min using a mechanicalstirrer. The mixture was transferred into a Teflon mold and was heatedon a hot plate at 80° C. for 1 h to facilitate the formation of a clearand transparent film. DSC thermogram of the product from 25° C. to 400°C.: Exotherms at 122° C. and 328° C.

Example 13

Thermal polymerization of diacetylene linkers in 4b (hydrosilated) toform 4b (polymerized)—A sample of a clear film of 4b (hydrosilated) wastreated in argon in a tube furnace at 250° C. for 30 min and at 400° C.for 2 h. The film was subsequently cooled to room temperature. The colorof the film had changed to dark red (“red form”) due to irreversiblethermal polymerization. Glass transition temperatures (T_(g)) (from −60°C. to 400° C. @ 10° C./min) of the film: 19.88° C., 50.44° C.; Noexotherms were observed as all diacetylene units had crosslinked onthermal polymerization.

Example 14

Synthesis of the crosslinker 5a from 3a and1,1,3,3,5,5,7,7-octamethyltetrasiloxane—1,1,3,3,5,5,7,7-Octamethyltetrasiloxane(0.1 g, 0.354 mmol) and 3a (0.155 g, 0.708 mmol) were mixed in 2 mL ofhexane in a vial and 90 μL (9.90 μmol of Pt) of the Karstedt catalystsolution was added and the mixture was mixed vigorously for 2 min usinga mechanical stirrer to obtain a viscous product. FT-IR: ν (—C≡C—C≡C—):2068 cm⁻¹ and ν (—CH═CH₂): 1594 cm⁻¹.

Example 15

Formation of the inorganic-organic hybrid hydrosilated dendritic network5a (hydrosilated) from reaction of 1 and the crosslinker5a—Octasilane-POSS 1 (0.50 g, 0.49 mmol) and 5a (1.232 g, 1.97 mmol)were mixed with 2.5 mL of toluene to yield a clear solution. To thissolution, 90 μL (9.90 μmol of Pt) of the Karstedt catalyst solution wasadded and the mixture was mixed vigorously for 5 min using a mechanicalstirrer. The mixture was transferred into a Teflon mold and was heatedon a hot plate at 80° C. for 1 h to facilitate the formation of a clearand transparent film. DSC thermogram of the product from 25° C. to 400°C.: Exotherms at 130° C. and 325° C.

Example 16

Thermal polymerization of diacetylene linkers in 5a (hydrosilated) toform 5a (polymerized)—A sample of a clear film of 5a (hydrosilated) wastreated in argon in a tube furnace at 250° C. for 30 min and at 400° C.for 2 h. The film was subsequently cooled to room temperature. The colorof the film had changed to dark red (“red form”) due to irreversiblethermal polymerization. Glass transition temperatures (T_(g)) (from −60°C. to 400° C. @ 10° C./min) of the film: −16.23° C., 47.86° C.; Noexotherms were observed as all diacetylene units had crosslinked onthermal polymerization.

Example 17

Synthesis of the crosslinker 5b from 3b and1,1,3,3,5,5,7,7-octamethyltetrasiloxane—1,1,3,3,5,5,7,7-Octamethyltetrasiloxane(0.1 g, 0.354 mmol) and 3b (0.330 g, 0.708 mmol) were mixed in 2 mL ofhexane in a vial and 90 μL (9.90 μmol of Pt) of the Karstedt catalystsolution was added and the mixture was mixed vigorously for 2 min usinga mechanical stirrer to obtain a viscous product. FT-IR: ν (—C≡C—C≡C—):2072 cm⁻¹ and ν (—CH═CH₂): 1596 cm⁻¹. DSC analysis (from RT to 400° C.at 10° C./min) in N₂ of 5b: Melting endotherm at 101° C. and exotherm at307° C.

Example 18

Formation of the inorganic-organic hybrid hydrosilated dendritic network5b (hydrosilated) from reaction of 1 and the crosslinker5b—Octasilane-POSS 1 (0.50 g, 0.49 mmol) and 5b (2.19 g, 1.97 mmol) weremixed with 2.5 mL of toluene to yield a clear solution. To thissolution, 90 μL (9.90 μmol of Pt) of the Karstedt catalyst solution wasadded and the mixture was mixed vigorously for 5 min using a mechanicalstirrer. The mixture was transferred into a Teflon mold and was heatedon a hot plate at 80° C. for 1 h to facilitate the formation of a clearand transparent film. DSC thermogram of the product from 25° C. to 400°C.: Exotherms at 128° C. and 328° C.

Example 19

Thermal polymerization of diacetylene linkers in 5b (hydrosilated) toform 5b (polymerized)—A sample of a clear film of 5b (hydrosilated) wastreated in argon in a tube furnace at 250° C. for 30 min and at 400° C.for 2 h. The film was subsequently cooled to room temperature. The colorof the film had changed to dark red (“red form”) due to irreversiblethermal polymerization. Glass transition temperatures (T_(g)) (from −60°C. to 400° C.@ 10° C./min) of the film: 19.47° C., 52.04° C.; Noexotherms were observed as all diacetylene units had crosslinked onthermal polymerization.

Example 20

Synthesis of the crosslinker 6a from 3a andbis[(p-dimethylsilyl)phenyl]ether—Bis[(p-dimethylsilyl)phenyl]ether (0.1g, 0.349 mmol) and 3a (0.152 g, 0.698 mmol) were mixed in 2 mL of hexanein a vial and 90 μL (9.90 μmol of Pt) of the Karstedt catalyst solutionwas added and the mixture was mixed vigorously for 2 min using amechanical stirrer to obtain a viscous product. FT-IR: ν (—C≡C—C≡C—):2072 cm⁻¹ and ν (—CH═CH₂): 1596 cm⁻¹.

Example 21

Formation of the inorganic-organic hybrid hydrosilated dendritic network6a (hydrosilated) from reaction of 1 and 6a—Octasilane-POSS 1 (0.50 g,0.49 mmol) and 6a (1.393 g, 1.97 mmol) were mixed with 2.5 mL of tolueneto yield a clear solution. To this solution, 90 μL (9.90 μmol of Pt) ofthe Karstedt catalyst solution was added and the mixture was mixedvigorously for 5 min using a mechanical stirrer. The mixture wastransferred into a Teflon mold and was heated on a hot plate at 80° C.for 1 h to facilitate the formation of a clear and transparent film. DSCthermogram of the product from 25° C. to 400° C.: Exotherms at 122° C.and 318° C.

Example 22

Thermal polymerization of diacetylene linkers in 6a (hydrosilated) toform 6a (polymerized)—A sample of a clear film of 6a (hydrosilated) wastreated in argon in a tube furnace at 250° C. for 30 min and at 400° C.for 2 h. The film was subsequently cooled to room temperature. The colorof the film had changed to dark red (“red form”) due to irreversiblethermal polymerization. Glass transition temperatures (T_(g)) (from −60°C. to 400° C.@ 10° C./min) of the film: 20.26° C., 54.63° C.; Noexotherms were observed as all diacetylene units had crosslinked onthermal polymerization.

Example 23

Synthesis of the crosslinker 6b from 3b andbis[(p-dimethylsilyl)phenyl]ether—Bis[(p-dimethylsilyl)phenyl]ether (0.1g, 0.349 mmol) and 3b (0.326 g, 0.698 mmol) were mixed in 2 mL of hexanein a vial and 90 μL (9.90 μmol of Pt) of the Karstedt catalyst solutionwas added and the mixture was mixed vigorously for 2 min using amechanical stirrer to obtain a viscous product. FT-IR: ν (—C≡C—C≡C—):2072 cm⁻¹ and ν (—CH═CH₂): 1596 cm⁻¹. DSC analysis (from RT to 400° C.at 10° C./min) in N₂ of 6b: Melting endotherm at 101° C. and exotherm at307° C.

Example 24

Formation of the inorganic-organic hybrid hydrosilated dendritic network6b (hydrosilated) from reaction of 1 and 6b—Octasilane-POSS 1 (0.50 g,0.49 mmol) and 6b (2.363 g, 1.97 mmol) were mixed with 2.5 mL of tolueneto yield a clear solution. To this solution, 90 μL (9.90 μmol of Pt) ofthe Karstedt catalyst solution was added and the mixture was mixedvigorously for 5 min using a mechanical stirrer. The mixture wastransferred into a Teflon mold and was heated on a hot plate at 80° C.for 1 h to facilitate the formation of a clear and transparent film. DSCthermogram of the product from 25° C. to 400° C.: Exotherms at 120° C.and 316° C.

Example 25

Thermal polymerization of diacetylene linkers in 6b (hydrosilated) toform 6b (polymerized)—A sample of a clear film of 6b (hydrosilated) wastreated in argon in a tube furnace at 250° C. for 30 min and at 400° C.for 2 h. The film was subsequently cooled to room temperature. The colorof the film had changed to dark red (“red form”) due to irreversiblethermal polymerization. Glass transition temperatures (T_(g)) (from −60°C. to 400° C.@ 10° C./min) of the film: 20.87° C., 55.24° C.; Noexotherms were observed as all diacetylene units had crosslinked onthermal polymerization.

Example 26

Synthesis of the acetylene analogs, 7a and 7b, of 3a and 3b—AnhydrousTHF (50 mL) and n-BuLi (46.7 mL, 2.5 M, 116.75 mmol) were transferred toa sealed 50-mL Kjeldahl reaction flask containing a magnetic stir bar.The reactions flask had been evacuated under vacuum and back-filled withargon prior to the additions. The flask was then immersed in a dryice/2-propanol bath. While stirring, trichloroethylene (3.5 mL, 38.9mmol) was added dropwise over 20 min, forming a pale yellow solution.The dry ice/2-propanol bath was removed and the reaction mixture waswarmed to room temperature with stirring over 2 h. The mixture was thencooled further in a dry ice/2-propanol bath andvinyldimethylchlorosilane (10.8 mL, 77.8 mmol) orvinyldiphenylchlorosilane (17.6 mL, 77.8 mmol) was added drop wise toinitiate the formation of 7a or 7b, respectively. The reaction mixturewas further warmed to room temperature with stirring over 2 h and thecontents were then poured into a saturated NH₄Cl solution (150 mL,aqueous) at 0° C. The reaction flask was then rinsed with Et₂O into theNH₄Cl quench solution. The resulting two-phase mixture was transferredto a 500-mL separatory funnel and washed with a saturated NH₄Cl (aq)solution until the pH was neutral and then two times with distilled H₂O.The organic phase was poured into an Erlenmeyer flask and dried overanhydrous Na₂SO₄ and activated carbon. The dried solution was filteredthrough celite into a round-bottomed flask, concentrated by rotaryevaporation, and then exposed to reduced pressure at room temperaturefor 5 h to yield 7a or 7b, respectively. (Ijadi-Maghsoodi et al., J.Polym. Sci.: Part A: Polym. Chem. 1990, 28, 955-965)

Obviously, many modifications and variations are possible in light ofthe above teachings. It is therefore to be understood that the claimedsubject matter may be practiced otherwise than as specificallydescribed. Any reference to claim elements in the singular, e.g., usingthe articles “a,” “an,” “the,” or “said” is not construed as limitingthe element to the singular.

1. An acetylene- and silicon-containing compound having the formula:

wherein n is a nonnegative integer; wherein m is 1 or 2; wherein thedashed bond is a single bond and the double dashed bond is a doublebond, or the dashed bond is a double bond and the double dashed bond isa triple bond; wherein each R is methyl or phenyl; and wherein R²comprises one or more of silane, siloxane, and aromatic groups.
 2. Thecompound of claim 1, wherein the compound is


3. The compound of claim 1, wherein the acetylene-containing compound is

wherein each R′ is methyl, alkyl, or aryl.
 4. The compound of claim 1,wherein the acetylene-containing compound is

wherein each R′ is methyl, alkyl, or aryl.
 5. The compound of claim 1,wherein the acetylene-containing compound is

wherein each R′ is methyl, alkyl, or aryl.
 6. A polymer made by ahydrosilation reaction of a polyhedral oligomeric silsesquioxane havingpendant siloxane groups with an acetylene- and silicon-containingcompound having at least two vinyl or ethynyl groups; wherein thereaction occurs between the pendant siloxane groups and the vinyl orethynyl groups.
 7. The polymer of claim 6, wherein the polyhedraloligomeric silsesquioxane is ((SiH(CH₃)₂O)SiO_(1.5))₈.
 8. The polymer ofclaim 6, wherein the acetylene-containing compound is

wherein m is 1 or 2; and wherein each R is methyl or phenyl.
 9. Thepolymer of claim 6, wherein the acetylene-containing compound includesone or more compounds having the formula:

wherein n is a positive integer; wherein each R is methyl or phenyl; andwherein each R′ is methyl, alkyl, or aryl.
 10. The polymer of claim 6,wherein the acetylene-containing compound includes one or more compoundshaving the formula:

wherein n is a positive integer; wherein each R is methyl or phenyl; andwherein each R′ is methyl, alkyl, or aryl.
 11. The polymer of claim 6,wherein the acetylene-containing compound includes one or more compoundshaving the formula:

wherein n is a positive integer; wherein each R is methyl or phenyl; andwherein each R′ is methyl, alkyl, or aryl.
 12. A crosslinked polymermade by crosslinking the acetylene groups in the polymer of claim
 6. 13.The crosslinked polymer of claim 12, wherein the polyhedral oligomericsilsesquioxane is ((SiH(CH₃)₂O)SiO_(1.5))₈.
 14. The crosslinked polymerof claim 12, wherein the acetylene-containing compound is

wherein m is 1 or 2; and wherein each R is methyl or phenyl.
 15. Thecrosslinked polymer of claim 12, wherein the acetylene-containingcompound includes one or more compounds having the formula:

wherein n is a positive integer; wherein each R is methyl or phenyl; andwherein each R′ is methyl, alkyl, or aryl.
 16. The crosslinked polymerof claim 12, wherein the acetylene-containing compound includes one ormore compounds having the formula:

wherein n is a positive integer; wherein each R is methyl or phenyl; andwherein each R′ is methyl, alkyl, or aryl.
 17. The crosslinked polymerof claim 12, wherein the acetylene-containing compound includes one ormore compounds having the formula:

wherein n is a positive integer; wherein each R is methyl or phenyl; andwherein each R′ is methyl, alkyl, or aryl.
 18. A method comprising:reacting, by a hydrosilation reaction, a polyhedral oligomericsilsesquioxane having pendant siloxane groups with an acetylene- andsilicon-containing compound having at least two vinyl or ethynyl groupsto form a polymer; wherein the reaction occurs between the pendantsiloxane groups and the vinyl or ethynyl groups.
 19. The method of claim18, wherein the reacting is performed in the presence ofPt₂{[(CH₂═CH)Me₂Si]₂O}₃.
 20. The method of claim 18, wherein thepolyhedral oligomeric silsesquioxane is ((SiH(CH₃)₂O)SiO_(1.5))₈. 21.The method of claim 18, wherein the acetylene-containing compoundincludes one or more compounds having the formula:

wherein n is a nonnegative integer; wherein m is 1 or 2; wherein each Ris methyl or phenyl; and wherein R² comprises one or more of silane,siloxane, and aromatic groups.
 22. The method of claim 18, furthercomprising: crosslinking the acetylene groups in the polymer.